One half of the sum over all permutations of [n] of the squared difference between the length of the longest increasing subsequence and the length of the longest decreasing subsequence.

A321278

One half of the sum over all permutations of [n] of the squared difference between the length of the longest increasing subsequence and the length of the longest decreasing subsequence.

Terms

    a(0) =0a(1) =1a(2) =4a(3) =18a(4) =105a(5) =699a(6) =5285a(7) =45128a(8) =431223a(9) =4540775a(10) =52268029a(11) =653096124a(12) =8810538490a(13) =127622293057

External references